中文摘要：

研究构建了pMDC32-NahG植物表达载体,并获得了其超表达的转基因烟草T1代株系。结果表明：这些株系与其野生型植株没有明显表型差异,但却表现出较野生型植株更敏感的青枯菌侵染抗性。同时,研究还发现NahG的超表达还显著提高了茉莉酸（JA）-依赖的基因NtPR1-b的表达,降低了（SA）-依赖的相关基因NtPR3和NtPRQ的表达。这表明SA累积的缺陷降低了烟草对青枯菌侵染的抗性。

英文摘要：

Studies showed that the plant expression vector of pMDC32-NahG was construed in tobacco K326,and ob- tained NahG-OE T1 lines. Comparing to wild type K326, NahG-OE lines did not exhibited any phenotypic differ- ence, but exhibited higher susceptibility to Ralstonia solanacearum inoculation. Meanwhile, it was found to be coupled with up-regulated expression of JA-depended NtPRI-b, and down-regulated expression of SA-depended NtPR3 and NtPRQ. Results suggested that SA-degrading NahG tobacco plants declined resistance to R. solanacearum infection.